Application of GRAS Compounds for the Control of Mould Growth on Scots Pine Sapwood Surfaces: Multivariate Modelling of Mould Grade

Olena Myronycheva,Tommy Vikberg,Dick Sandberg,Faksawat Poohphajai,Helmut Junge,Margot Sehlstedt-Persson,Olov Karlsson

doi:10.3390/f10090714

Olena Myronycheva, Tommy Vikberg + Show 5 more

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https://doi.org/10.3390/f10090714

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Abstract

Research Highlights: In this study, the Generally Recognised as Safe (GRAS) compounds were applied in order to study mould-fungi growth on dried Scots pine sapwood. Background and Objectives: The transition to the use of more sustainable wood-material may be possible by applying GRAS compounds that can control and prevent contamination by primary colonising mould fungi. Materials and Methods: Kiln-dried sawn timber was treated with three different GRAS compounds, and different fungal inoculation methods applied in order to investigate differences in the development of fungal communities. Results: Substances based on potassium silicate significantly reduced fungal growth and mould contamination on the studied wood surfaces. By combining wood-surface treatments with GRAS compounds, fungal-area size as predictors and mould grade as response, a partial least squares (PLS) model that makes it possible to predict mould grade on wood surfaces was developed. The PLS model is a key component in the development of a smart grading-systems equipped by e.g. high-speed digital cameras for the early detection of fungal attack on wood surfaces in different applications. However, the measurements based on chemical characterisation should be the next step to take in order significantly to enhance the model and increase the range of robust applications. In the current study, a multivariate model describing the influence of each fungal-covering area on mould grade was presented for the first time.

Highlights

The negative load of fossil- and petrol-based biocidal substances on the environment and the reduction of volatile organic compounds (VOCs) emitted while using solvent-based coatings, require the introduction of new concepts for wood-surface treatment for outdoor and indoor applications [1,2].A significant problem when wood is used and the moisture level is high, e.g. in outdoor conditions, is biodegradation caused primarily by fungi which have a unique nutrient-sensing mechanism [3]which makes the task of wood protection difficult
This study has investigated the efficiency of treatments using selected Generally Recognised as Safe (GRAS) compounds of organic and inorganic origin to restrict mould-fungi growth on wood surfaces of industrial kiln-dried
I.e. free from defects and knots, with dimensions of 30 × 50 × 100 mm, were taken from each board so that they contained only sapwood, which was verified by a heartwood reagent containing sodium nitrite and sulfanilic acid. Two of these specimens were used for density and moisture content (MC) determinations, according to EN 13183-1 [17], the other eight were used for mould tests and were coded according to the GRAS treatment applied before the mould test (Table 1)

Summary

Introduction

The negative load of fossil- and petrol-based biocidal substances on the environment and the reduction of volatile organic compounds (VOCs) emitted while using solvent-based coatings, require the introduction of new concepts for wood-surface treatment for outdoor and indoor applications [1,2].A significant problem when wood is used and the moisture level is high, e.g. in outdoor conditions, is biodegradation caused primarily by fungi which have a unique nutrient-sensing mechanism [3]which makes the task of wood protection difficult. The negative load of fossil- and petrol-based biocidal substances on the environment and the reduction of volatile organic compounds (VOCs) emitted while using solvent-based coatings, require the introduction of new concepts for wood-surface treatment for outdoor and indoor applications [1,2]. A significant problem when wood is used and the moisture level is high, e.g. in outdoor conditions, is biodegradation caused primarily by fungi which have a unique nutrient-sensing mechanism [3]. Which makes the task of wood protection difficult. Environmental processes that affect the wood in outdoor use result in aesthetic concerns and increased maintenance costs [4]. Fungal bio-aerosols accumulating on outdoor building-material surfaces may have a significant impact on indoor biological contamination, especially under sub-arctic conditions [5].

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